1. Field of the Invention
The invention relates to a touch display apparatus and a touch position mapping method thereof. More particularly, the invention relates to a touch display apparatus employing one fitting function and a touch position mapping method of said touch display apparatus.
2. Description of Related Art
With an advancement of semiconductor technologies, human beings by degrees tend to rely on electronic products. The electronic products such as mobile phones, handheld personal computers (PCs), personal digital assistants (PDAs) and smart phones have pervaded everywhere in our daily life. Some of the electronic products may integrate touch panels into display panels, so as to enable users to have relatively large display frames in a simple operation mode in consideration of restricted volumes of the miniature electronic products. The integration of the touch panels and the display panels results in a formation of a touch display panel. The touch display panel combines displaying function of a display panel and operating convenience of a touch panel. Therefore, the touch display panel has gradually become a standard equipment of many electronic devices.
Generally, a touch display panel includes a display panel and a touch panel. By disposing the display panel to overlap with the touch panel, based on the touch position detected by the touch panel, the display panel may display a corresponding screen or an electronic device using the touch display panel may execute a corresponding operation. FIG. 1 is an overlapping schematic view of a display panel and a touch panel. As shown in FIG. 1, a size of a display panel 102 is generally smaller than a size of the touch panel 104. However, a border area of the touch panel 104 does not include a touch-sensing functionality. Therefore, a touch area of the touch panel 104 is practically smaller than the area of the touch panel 102, namely, a touch area of the touch panel may not cover the entire area of the display panel 102.
Generally, the touch area on the touch display panel may be divided into a center touch area where most of touch operations from users are performed, and a border touch area where relatively fewer operations are performed. While having more error tolerance to the border touch area, the system manufacturer demands a higher accuracy in manufacturing the center touch area.
Since a relative relation of a touch-sensing unit of the touch panel 104 and a pixel unit of the display panel 102 is not a one-to-one correspondence, and the touch area of the touch panel 104 is smaller than the display area of the display area 102, such that computations may be required in order to match the touch position on the touch panel 104 to a corresponding position on the display panel 102. In conventional art, the mapping of the touch positions of the touch panel and the display panel is usually performed by using two independent functions, in which the two functions respectively define a portion of position range for position-mapping. Although said method may acquire a correct relative relation from most of the touch area, when the touch position falls on a boundary of the position ranges defined by the two function, the touch position of the touch panel 104 may not be accurately mapped to a corresponding position on the display panel 102, thereby affecting operative quality of the touch display panel.